1. Field of the Invention
The present invention relates generally to a flushing system for tank-type toilets and, more particularly to an automatic flushing system with buoyancy-actuating means to actuate flush valve.
2. Discussion of the Related Art
U.S. Pat. Nos. 5,169,118 and 5,244,179 relates to an automatic operated toilet room flush valve, wherein a solenoid operated automatic flush valve, which is battery-operated and utilizes a latching solenoid to limit power drain on the battery. Accordingly, when the infrared sensor detects the presence of a user of a toilet, the flush valve is automatically driven to open to complete the flushing operation.
U.S. Pat. No. 5,054,132 relates to a flush control system for a plumbing fixture having electrical components that electrically operate a flush valve, wherein an electrical circuit is activated to lift a normally closed cover for a predetermined time. When the cover is subsequently lowered, the flush valve is actuated for a second predetermined time. U.S. Pat. No. 3,590,397 relates to an automatic flushing device for a toilet, wherein the flushing of water is controlled by a switch actuated by a lid, such that, when the lid is opened, a control circuit opens a flush valve for a predetermined period of time to flush the toilet prior to use, and when the lid is closed after use, the control circuit again opens the valve for a predetermined period of time to flush the toilet again. U.S. Pat. No. 2,200,687 relates to a toilet bowl in which the seat and cover members may be automatically closed under predetermined conditions after being shifted to a raised position, and in which a mechanism is incorporated for coactions with one of the seat and cover members as it is moved to a closed position for actuating the flushing valve of the toilet. U.S. Pat. No. 1,313,740 relates to a manually operated mechanism for raising the cover of a toilet bowl and for lowering the cover and flushing the bowl, the mechanism including a pivotally mounted and manually operated lever which is connected, through the medium of a bar, to the cover, which lever engages and idly operates a pivoted pawl upon the raising action of the cover, and strikes and operates the pawl in a movement which lowers the cover for operating the flushing mechanism to flush the bowl simultaneously with the lowering of the cover.
U.S. Pat. No. 1,287,113 relates to a toilet flushing mechanism that includes a longitudinally movable bar that is connected to a pivoted cover or seat of a toilet bowl, and a plurality of pawls and levers that are controlled by the depressions of foot rods for moving the bar longitudinally to move the pivoted seat and also to operate the flushing mechanism of the toilet at the time when the seat is started to be moved into a closed position.
All other prior arts related to toilet flushing automation require alterations to existing flush mechanism of the existing toilet to achieve the purpose of control, the present invention retrofits with existing tank-type toilet and works with existing manual flush mechanism. No structure alteration is required for existing tank toilet.
In addition, all other flush actuation prior arts did not consider utilizing the natural resource, buoyancy, to actuate flush valve, hence automation for such a actuation device requires more power or energy; battery application is impractical, either require larger size of battery and motor or require power from A/C power supply; furthermore, the life cycles of batteries were dramatically shorter and require significant more cost of maintenance.
Neither of these systems previously proposed, however, combine the desirable characteristics of being economical, durable, simple to operate and install by user.